DE 297 20 776 discloses a deflection pulley having a grooved ball bearing which is surrounded on the outside by a molded-on pulley shell of plastic. The deflection pulley is secured by retainers comprised of a sealing disk and a screw which has a guide section received in the inner ring of the rolling-contact bearing of the deflection pulley. The outer circumference of the sealing disk forms at a same time a seal for the rolling-contact bearing. Provided in the center of the sealing disk is a cup-shaped stamped-in area having a cylindrical portion pressed into the bore of the inner ring of the rolling-contact bearing. The central bore of the sealing disk is provided to receive the guide section of the securing screw. The screw head is supported by an end surface of the inner ring by way of the sealing disk. The guide section extending from the screw head is provided to center the screw with respect to the inner ring of the rolling-contact bearing. To hold the retaining member captive and to secure it for transport, the sealing disk is provided adjacent the stamped-in area with elastic tongues distributed around the periphery and pressing at a slant in the axial/radial direction against the shaft of the securing screw. This transport safety system thus includes a sealing disk of complex configuration which incurs not only high manufacturing costs but complicates the installation.